<html>
<head>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
test(function() {
  assert_true(window instanceof Window, "Should be Window");
  assert_true(document.documentElement instanceof HTMLHtmlElement, "Should be HTMLHtmlElement");
  assert_true(document.documentElement.firstChild instanceof HTMLHeadElement, "Should be HTMLHeadElement");
  assert_equals(document.documentElement.nextSibling, null);
  assert_true(document instanceof Document, "Should be Document");
});
</script>
</head>
</html>
